CkPython

Receive a 4-byte Length Prefix from a Socket

Demonstrates Socket.ReceiveCount, which reads a four-byte length prefix as a signed 32-bit integer. A return value of -1 indicates failure.

Background. Reading the length prefix first tells the application exactly how many bytes to read for the message body, which is a reliable way to know when a full message has arrived.

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CkPython

import sys
import chilkat

success = False

socket = chilkat.CkSocket()

#  Connect to the server using TLS.
bTls = True
maxWaitMs = 5000
success = socket.Connect("example.com",5000,bTls,maxWaitMs)
if (success == False):
    print(socket.lastErrorText())
    sys.exit()

#  Read a four-byte length prefix as a signed 32-bit integer (network byte order by default).  A
#  return value of -1 indicates failure.
messageLength = socket.ReceiveCount()
if (messageLength < 0):
    print(socket.lastErrorText())
    sys.exit()

print("The peer will send " + str(messageLength) + " bytes.")